1. Field of the Invention
The field of the invention is hydro-demolition devices and methods for removing refractory from refractory-lined structures.
2. Description of Related Art
Hydro-demolition—or hydraulic demolition—is a well known art practiced by forcing an erosive material, generally a liquid such as water, through nozzles at sufficiently high pressure to produce a jet stream that disintegrates the constituent building material, normally concrete, of which buildings and structures are made.
The term “refractory” as used herein refers to heat resistant material.
The term “refractory-lined structure” or “RLS” refers to a pipe, riser, cyclone, boiler, kiln, oven, or other structure having an inner lining made of refractory.
The terms “cut,” “cutting,” and “cutter,” etc. as used herein refer to the use of hydro-demolition technology to remove refractory from an RLS.
The use of refractory to line conduits, risers, boilers, cyclones, kilns, and the like is a well known art and essential in many industries. For instance, in the art of fluid catalytic conversion (FCC) of hydrocarbons to produce petroleum products, refractory protects the walls of reactor risers from the extreme temperatures required to crack the hydrocarbon feedstocks.
Because refractory cokes, the working life-time of refractory is limited. Once coking becomes severe it is necessary to remove the coked refractory and replace it with fresh material. Failure to do so results in poor riser hydrodynamics, which causes sub-optimal, inadequate fuel and catalyst mixing. The ultimate result is decreased hydrocarbon conversion and product yield, which increases the price of the petroleum products to consumers.
Currently, removing coked refractory from RLS's is an arduous and expensive process for it must be done manually. The material is chipped away by hammers and chisels. For instance, it may take as many as twenty shifts in order to remove coked refractory from a refinery riser. Given that such a refinery may be producing millions of dollars of product per day, the costs of down time for refractory removal also adds significantly to the cost of petroleum products. Consequently, a system and a method are needed to more quickly and efficiently remove refractory from RLS's.
The present invention is such a system and method that employs hydro-demolition techniques and novel equipment in order to exploit the power of hydro-demolition.